Barge



Nov. 30, 1937. 1 A. J. DAWSON 2,100,472

BARGE Filed June 6, 1956 INVENATOR dfiw .Qawam.

BY 6 mafia/[25C ATTO R N EYS Patented Nov. 30, 1937 UNITED STATES BARGE Albert J. Dawson, Sewickley, Pa., assignor to The Dravo Contracting Company, a corporation of Pennsylvania Application June 6,

1 Claim.

This invention relates to the structure of steel barges, such as are used in river transportation and elsewhere, for carrying heavy cargoes, ordinarily in bulk. These barges are fiat bottomed,

5 vertical sided, and rake-ended.

The invention is illustrated in the accompanying drawing. Fig. I is a view in side elevation of a barge embodying the invention. Fig. II is a fragmentary view in plan, showing one of the duplicate ends of the barge. Fig. III is a view to larger scale, showing the barge in end elevation. Figs. IV and V are fragmentary views, corresponding to Fig. I, and illustrating variations in detail in the embodiment of the invention.

The flat bottom of the barge of the drawing is indicated at I; the vertical side-walls at 2; and the rake-ends at 3.

The angle of meeting of the bottom and sidewalls is, as commonly is the case, rounded, as

indicated at 4. This rounding is, by extension of the meaning of the work, commonly called the bilge. The radius of curvature of such rounding is commonly of the order of 12 inches (it varies, but seldom is it less than 6 nor more than 24 25 inches). In any case it continues, in barges that heretofore have been built, of constant value throughout the extent both of the parallel middle portion of the barge, and of the rake-ends as well.

The invention consists in the discovery that, by increasing, in the rake-ends only of the barge, the radius of curvature of the bilge, the resistance that the barge ofiers to propulsion may to substantial and valuable degree be diminished.

There are practical considerations, limiting the value of the radius of curvature of the bilge throughout the parallel middle portion of the barge, and forbidding its increase. These are that as this radius is increased the displacement Q of the barge is diminished; as this radius is increased, a tendency of the barge to slide in turning is increased; and as the radius is increased the cost of construction is increased. In the rake- .ends, however, increase of the radius of bilge be- 1936, Serial No. 83,907

yond that to which, for the reasons already given, the radius elsewhere is limited will, as I have discovered by actual test, afford a gain in reduced resistance to propulsion that more than offsets any disadvantage or loss.

As shown in Figs. I and III the radius of curvature in the bilge-4 throughout the parallel middle portion of the barge is of smaller value (say 12 inches) the. radius throughout the rake-ends, to which the numeral is applied, is of larger value (say 30 inches); and the two cylindrical surfaces 4 and 40' merge one into the other through an intermediate conical surface 5 of small extent at the base of the rake-end. Alternatively, as shown in Fig. IV, the radius of curvature increases gradually from the base to the tip of the rake-end, forming the bilge surface 4|. As shown in Fig. V, the radius of curvature increases gradually, as in the case of the structure of Fig. IV, to or beyond the normal waterline, as indicated at 42, and then diminishes again through a region 43, to a minimum at the tip of the rake-end. The reason for this last described refinement is to produce a barge whose square end 6 (of. Figs. II and III) shall have maximum extent in transverse direction. Maximum extent of this end face is of value in making barges up into fleets.

In the shaping of the bilge the curvature may be circular in every vertical and transverse plane, throughout all the length of the barge; or, in the rake-ends, the curvature may be circular in transverse planes perpendicular to planes tangent to the bottom wall.

I claim as my invention:

A barge structure including a body having parallel walls and a rake-end in which the side and bottom walls meet in a bilge curve, the radius of bilge curvature being uniform throughout the body and increasing in the rake-end from that 40 of the body outwardly to a maximum and then decreasing again.

ALBERT J. DAWSON. 

